Results 211 to 220 of about 5,682 (254)

Measurement of Protoporphyrinogen Oxidase Activity

Current Protocols in Toxicology, 1999
AbstractProtoporphyrinogen oxidase catalyzes the oxidation of protoporphyrinogen to protophyrin. It is a membrane‐bound mitochondrial enzyme and it is the target of photobleaching herbicides. The basic assay presented in this unit for measuring oxidase activity is based on oxidation of the colorless, nonfluorescent substrate, protoporphyrinogen, to the
J M, Jacobs, N J, Jacobs
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Three trifluoromethyl-substituted protoporphyrinogen IX oxidase inhibitors

Acta Crystallographica Section C Crystal Structure Communications, 2005
The structures of methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate, C15H9ClF3N3O5, (I), methyl 2-chloro-5-[3-methyl-2,6-dioxo-4-(trifluoromethyl)-1,2,3,6-tetrahydropyrimidin-1-yl]benzoate, C14H10ClF3N2O4, (II), and 2-[4-chloro-2-fluoro-5-(prop-2-ynyloxy)phenyl]-4-(trifluoromethyl)piperidine-2,6-dione, C15H10ClF4NO3, (III), are similar in ...
Bin, Li, Yu Ming, Lan, Chi Tung, Hsu, Zhen Long, Liu, Hai Bin, Song, Chao, Wu, Hua Zheng, Yang   +6 more
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Protoporphyrinogen Oxidase-Inhibiting Herbicides

Weed Science, 1991
Several commercial and experimental herbicides such asp-nitrodiphenyl ethers, oxadiazoles, and cyclic imides inhibit protoporphyrinogen IX oxidase (Protox), the enzyme that converts protoporphyrinogen IX to protoporphyrin IX (Proto). This leads to uncontrolled autooxidation of the substrate and results in accumulation of Proto.
Stephen O. Duke, John Lydon, José M. Becerril, Timothy D. Sherman, Larry P. Lehnen, Hiroshi Matsumoto   +5 more
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Mitochondrial targeting of human protoporphyrinogen oxidase

Cell Biology International, 2006
Variegate porphyria is an autosomal dominant disorder of heme metabolism resulting from a deficiency in protoporphyrinogen oxidase, an enzyme located on the inner mitochondrial membrane. This study examined the effect of three South African VP-causing mutations (H20P, R59W, R168C) on mitochondrial targeting.
Lester M, Davids, Anne V, Corrigall, Peter N, Meissner   +2 more
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Fluorometric assays for coproporphyrinogen oxidase and protoporphyrinogen oxidase

Analytical Biochemistry, 1985
We describe fluorometric assays for two enzymes of the heme pathway, coproporphyrinogen oxidase and protoporphyrinogen oxidase. Both assays are based on measurement of protoporphyrin IX fluorescence generated from coproporphyrinogen III by the two consecutive reactions catalyzed by coproporphyrinogen oxidase and protoporphyrinogen oxidase.
P, Labbe, J M, Camadro, H, Chambon
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Characteristics of Protoporphyrinogen Oxidase

1999
Protoporphyrinogen oxidase (EC 1.3.3.4) catalyzes the oxidative O2-dependent aromatization of the colorless protoporphyrinogen IX to the highly conjugated protoporphyrin IX, the precursor of both hemes and chlorophylls (Fig. 1). It is the final enzyme in the common branch of the heme and chlorophyll biosyn-thetic pathways in plants (Fig. 2).
Camadro, J.M., Arnould, S., Le Guen, L., Santos, Raphael, Matringe, Michel, Mornet, R.   +5 more
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Protoporphyrinogen oxidase and ferrochelatase in porphyria variegata

European Journal of Clinical Investigation, 1983
Abstract. Protoporphyrinogen oxidase activity and ferrochelatase activity were measured in leucocytes from patients with porphyria variegata. The mean activity of protoporphyrinogen oxidase (PPO) in porphyria variegata (PV) was about 50% of normal (P < 0.05). The mean activity of ferrochelatase with 59Fe2+ sulphate and protoporphyrin as substrates (
D J, Viljoen, R, Cummins, J, Alexopoulos, S, Kramer   +3 more
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Protoporphyrinogen Oxidase-Inhibiting Herbicides

2010
Publisher Summary Protoporphyrinogen oxidase-inhibiting herbicides, also referred to as Protox- or PPO-inhibiting herbicides, were commercialized in the 1960s. Nitrofen was the first Protox-inhibiting herbicide to be introduced for commercial use in 1964.
Franck E. Dayan, Stephen O. Duke
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Purification and characterization of murine protoporphyrinogen oxidase

Biochemistry, 1987
The penultimate enzyme of the heme biosynthetic pathway, protoporphyrinogen oxidase (EC 1.3.3.4), has been purified to apparent homogeneity from mouse liver mitochondria. The purification involves solubilization from mitochondrial membranes with sodium cholate followed by ammonium sulfate fractionation and gel filtration on a Sepharose CL-6B column ...
H A, Dailey, S W, Karr
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Enantioselectivity of protoporphyrinogen oxidase‐inhibiting herbicides

Pesticide Science, 1994
AbstractProtoporphyrinogen oxidase (Protox) was inhibited stereoselectively by three pairs of enantiomers belonging to diphenyl ether (DPE) and pyrazole phenyl ether (PPE) herbicide classes. The (R) enantiomers were 10‐ to 44‐fold more active than the (S) enantiomers as inhibitors of Protox from barley etioplasts.
Ujjana B. Nandihalli, Mary V. Duke, John W. Ashmore, Vincent A. Musco, Robert D. Clark, Stephen O. Duke   +5 more
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